Leverage Android Q Thermal API to request low bit rate stream as needed

### [REQUIRED] Use case description
Android devices getting warm can throttle CPU/GPU and this could affect streaming performance.

### Proposed solution
Android Q provides thermal API for apps to be notified and fallback to low performance mode. These callbacks could be used by ExoPlayer to request low quality stream from multiple tracks (if available).

### Alternatives considered
Android Apps could do this logic explicitly but this is something all apps would need and an out of box solution from ExoPlayer would help avoid redoing logic across applications.